The present invention relates to a capstan drive type magnetic recording tape drive apparatus and, more particularly, to a capstan drive type magnetic recording tape drive apparatus using a cassette tape called a micro-cassette.
In a conventional capstan drive type magnetic recording tape drive apparatus of the type described, when the magnetic recording tape of the micro-cassette travels in one direction, one of a pair of reel shafts becomes the shaft of a take-up reel and the other becomes the shaft of a supply reel. When the magnetic recording tape travels in the other direction, the other of the pair of reel shafts becomes the shaft of the take-up reel, and the former becomes the shaft of the supply reel. The switching between reel shafts is effected by switching the transmission of the driving force of a driving means by disposing an idler or a unidirectional clutch means with each reel shaft. With such a construction, the driving force of the driving means is not transmitted to the shaft of the supply reel so that the shaft of the supply reel slips. Thus, the shaft of the supply reel sometimes rotates at a speed faster than the traveling speed of the magnetic recording tape in the same direction as the magnetic recording tape when it travels from the shaft of the supply reel to the shaft of the take-up reel. This phenomenon results in the generation of an irregular change in the back tension at a portion of the magnetic recording tape between the supply reel shaft and the take-up reel shaft. This irregular change in the back tension in turn causes wow and flutter.